This one indicates the M3 is common in populations as recent as 14KYA.

An older study (back in the 80s) shows detailed gracilization studies of
human skeletal materials in the UK from about 10KYA indicating that the
continued reduction in the facial skeleton was fairly recent.

The problem with most of the studies on current populations is that you
have to look at a bunch of individual articles about dental development
in Turkey, or Japan, or among Hispanic children in Texas, and so on. A
couple of studies indicate that there is considerable variation ---
which is probably environmentally mediated --- even between regions in
the US.

However, the growth rates of the jaw apparatus seem to have a
significant effect on the rate of mineralization of the crowns and
development of the roots.

I also found this, but could not access it: DAHLBERG AA
THE CHANGING DENTITION OF MAN
JOURNAL OF THE AMERICAN DENTAL ASSOCIATION 32 : 676 1945

The current dental literature reports that PAX9 seems to be the homeobox
gene that is most commonly found in third molar agenesis. But we are
also seeing MX1 and TGFA showing up in some studies. Other studies show
that it is not the structural gene PAX9, but promoter region G/C-915
that makes the difference.

All this means simply that --- like most anatomical features --- there
is a complex interaction at the level of structural, regulatory, and
developmental genes that influence the outcomes.

Bob Muckle wrote:

>
>
> Can anybody familiarize me with the anthropological perspective on
> having no room for the third molars (wisdom teeth)? Some the things I
> would like to know include
>
> When did having no room for the third molar start appearing in the
> archaeological record (in populations, rather than individuals)?
>
> How widespread is this phenomena around the world?
>
> What are some of the explanations/hypotheses used to explain it?
>
> I'm guessing that some kind of cutlural selection processs has been
> going on (ie. less prognathism=more attractive, but less room for
> teeth), but don't really know. I assume that the loss of four molars
> would generally be a bad thing, considering that it would put
> increased wear on the remaining molars. I'm also under the impression
> that it is becoming increasingly common for people to never have their
> third molars appear (thus not having to have them extracted). But this
> is anecdotal only.
>
> Make me, or let me, look smart to my students. Please.
>
> Bob
>
>